Rails：使CGI :: escape在模型中工作？

Question

我在模型中尝试了以下两种方法：

CGI.escape(default_url)

CGI::escape(default_url)

每次我收到此错误：

undefined method 'encoding' for nil:NilClass

Answer 1

必须执行default_url.to_s，因为在某些情况下它已设置为nil

Answer 2

检查：ActiveSupport#to_query

# File activesupport/lib/active_support/core_ext/object/to_query.rb, line 8
def to_query(key)
  require 'cgi' unless defined?(CGI) && defined?(CGI::escape)
  "#{CGI.escape(key.to_param)}=#{CGI.escape(to_param.to_s)}"
end